Speedo / Scan Gauge Question

Ran the new truck with the Scan Gauge and Magellan GPs hooked up today. GPS and Scan Gauge read 70mph and the Speedo has the needle just enough past 70 that it shows white on the left side so I would guess 72-73mph reading. The question is, with the Odometer being digital, does it read from the same source as the Scan Gauge does? If so then I assume that the mileage readings would be correct and the actual speedometer simply registers a tad high.

 

You could use the mile-markers on the highway and the trip-meter to verify, but I think the speedo reads high for liability purposes. The odo should be fine, assuming stock tire diameter.

 

Common practice among manufacturers to limit liability. Avoids lawsuits ie "but my speedometer said I was only doing 65". Usually 2-3 mph high.

Remember also that both speedometer and odometer accuracy will change as tires wear, so worn tires travel less distance than new ones, but the same number of revolutions are reported/recorded by the speed sensor.